Traffic signal circuit



Nov. 8, 1932. D. H. CALDERWOOD 1,885,523

TRAFFIC SIGNAL CIRCUIT I Filed April 25. 1930 32 jazz/wi ZYVQaiMZ N V EN TO R ATTOR N EY-$ Patented Nov. 8, 1932 DAVID HARLOW CALDERWOOD, OF JOHNS'IOWN, NEW YORK TRAFFIC SIGNAL CIRCUIT Application filed April 23,

The object of the invention is to provide a circuit arrangement for use in conjunction with the conventional crossing signals, whereby a siren may be incorporated and operated at times or in periods of danger and all of the danger signals simultaneously operated and this without any modification of the conventional signal, insofar as wiring changes are necessary, except such additional leads 0 as are. necessary to connect the additional parts employed in circuit.

With this object in view, the invention consists in a construction and arrangement of parts of which a preferred embodiment is illustrated in the accompanying drawing which is a diagrammatic view or" a conventional crossing signal with the apparatus ineluded in the invention connected in circuit.

In the drawing the lamps R, A and G and R, A and G are grouped according to the conventional fashion, the one group being observable from one direction and the other group from an angularly related direction. hen the main or R light observable from one direction is illuminated the corresponding G light observable from the other direction must be illuminated. Likewise, the R light and G light must be simultaneously illuminated. Therefore, the positive terminals of the R light and G light are connected in on a lead 10, terminating at the binding post 11. Likewise, the positive terminals of the R light and G light are connected in on a lead 12 carried to a binding post 14, the positive terminals of the A and A lights being connected to the binding posts 15 and 16 by the leads 17 and 18. The negative terminals of the lights G and G are connected, by means of a conductor 19, with a binding post 20, as are also the negative terminals of the leads A and A. The negative terminals of the leads R and R are connected by means of a conductor 21 with a binding post 22.

The above constitutes the circuit arrangement of a conventional trafiic signal.

In incorporating the invention, the siren or audible signal 23 is connected across the binding posts 22 and 20.

The rotary time switch 24 which is of conventional form has its collector ring 25 con- 1930. Serial No. 446,666.

nected by means of a conductor 26 with one terminal of a double-pole switch 27 and its segments 28, 29, 30 and 31 connected respectively to the bind-posts 11, 14, 15 and 16. The opposite pole of the switch 27 is connected by means of a conductor 32 with a binding post 22.

A triple-pole relay constitutes the element necessary to be included in circuit to carry out the invention and it has one of its arms 33 connected to the binding post 20 and the other arms 34 and 35 connected together and to a conductor 36 tapped in on the conductor 26. The arms 33, 34 and 35 are connected for synchronous movement and the arms 34 and 35 are adapted to be brought into engagemetn with the contacts 37 and 38 or separated therefrom, while the arm 33 is engaged with the contact 40 in one position of the relay and with the contact 39 in the other position. The relay is actuated by means of a spring 41 to hold the arms in position where the arm 33 will be engaged with the contact 40 and separated from the contact 39, the arms 34 and 35 being correspondingly separated from their respective contacts 37 and 38. A solenoid 42 constitutes an element of the relay to actuate the arms i1: opposition to the spring 41 and this solenoid is connected across the conductors 36 and 32 and is controlled by a manual switch 43.

The contact 39 is connected by means of a conductor 44 with the conductor 26 while the contact 40 is connected with the binding post 22 and the contacts 37 and 38 are connected to the binding posts 11 and 14 which may be done by tapping in on the conductors leading from the segments 28 and 29 to said binding posts.

In the operation of the invention the switch 43 is normally open, being designed for closure by hand actuation. When the switch 27 is closed, however, the feed line is connected in on the signal and it operates in the usual way when the time switch 24 rotates, current passing from one of the line conductors to one pole of the switch and thence over the conductor 26 to the collector ring 25 and thence to the different sectors of the time switch 24. If the sector 28 is in circuit closing position, the current flows to the binding post 11 and thence over the conducof the current and returning to the source over the conductor 32. V7 hen the time switch will have moved to a position that will render the segment 28 inoperative, the segments 30 and 31 will be rendered operative to connectthe positive lead in on the bindlng posts 15' and 16, so that current will pass through the lampsA and A and to the bindmg post 20 over the conductor 19, reaching the binding post 22 through the switch arm and contact 40 and thence returning to the source as when the R and G lights were illuminated. Further angular movement of terminal of the R light, returning from the the time switch will render thesegment 29 operative and current will then pass to the binding post 14 and'thence to the posltlve terminal ofthe G light and corresponding negative terminal of the latter to the binding post 22 and from the negative terminal of the former to the binding post 20, the arm 33, contact 40 and binding post 22, returning to .the'source over the conductor 32.

When it is desired to operate the audible signal or siren and render both the R and R signals operative, the switch 43 is closed manually, which will result in energizing the solenoid 42 by which current will be supplied rom the source over the conductor 36, through the solenoid, over the switch 43 and back over the conductor 32. The arms 33, 34 and 35 of the relay will then be moved to engage the contacts 39, 38 and 37, when the timeswitch 24 will'be rendered inoperative, since current will then pass over the conductor 36 to the arms 34' and 35 and thence to the contacts 38 and 37 and to the binding posts 14 and 11 and over the conductors l2 and 10 to the positive terminals of the lights R and R and thence from the negative terminals of the latter over the conductor 21 to the binding post 22 and thence back to the source over the conductor 32. But with the engagement of the arm 33 with the contact 39, the current leaving the positive pole of the switch willdivide, part passing-over theconductor 44 to the contact 39 and thence over the arm 33 to the binding post 20, making that positive, whereas in previous operations itwas negative. This change in potential oi' the binding post 20 places the siren 23' across-the supply -line by reason of the binding posts 20 and 22 beingthen positive and negative. Thus, the siren will be subject to an energizing current and will be put in operation. The lights A, A, G and G wlll be rendered inoperative despite the rotat on of the time switch 24 because their negative terminals are connected in on the binding post 20 which in the normal or spring retracted position of the relay is negative but which in the energized position of the relay is made positive and thus brought to the same potential as the positive terminals of the lamps A, A, G and G.

Opening the switch 43 of course permits spring actuation of the relay and the restoration of the parts to normal position where the signals Will operate in the conventional fashion. r I

The invention having been described, what is claimed as new and useful is:

1. In combination with a trafiic signal having a plurality of sets of electrically energized clear and danger signals of whichthe positive terminals of the danger signals of one set are connected to the positive terminals of the clear signals of another set'and the negative terminals of the clear signals and the negatlve terminals of thedanger sig'-' nals of different sets are respectively (5on nected together-,a time controlled switch interposed between the positive side of a supply source and said positive terminals to alternately energize the same, the negative terminals of the danger signals being connected in on the negative side of the supply source, a relay having a movable element connected to the negative terminals of the clear signals, and a pair otfixed contacts with either of which said movable element is engageable, one of the fixed contacts being connected in on the negative side of the supply source and the other being connected in onthe'positive side of the supply sourceand an audible sig nal connected between said movable element and the negative side of saidsupply source. 2. In combination with a traific signal having a plurality of sets of'electrically energized clear and danger'signals of which the positive terminals of the danger signals of one set are connected to the positive terminals of the clear signals of another set and the negative terminals of the clear signals and the negative terminals of the danger signals of difierent sets are respectively connected together, a time controlled switch interposed between the positive side of a supply source and said positive terminals to alternately energlze the same, the negative terminals of the danger signals being connected in on the negative side of the supply source,

a relay having a movable element connected to the negativeterminals of the clear signals, and a pair of fixed contacts with either of which said movable element is-engageable, one of the fixed contacts being connected in on the negative side of the supply-sourceand the other being connected in on the positive JIM.

side of the supply source and an audible sig nal connected between said movable element and the negative side of said supply source, the relay including a plurality of additional movable members connected in on the positive side of the supply source, and fixed contacts respectively connected in between the time switch and the positive terminals of said signals, the last said contacts being engageable by the last said movable elements when the first said movable element is engaged with that contact connected in on the positive side of the supply source.

3. In combination with a trafiic signal having a plurality of sets of electrically energized clear and danger signals of which the positive terminals of the danger signals of one set are connected to the positive terminals of the clear signals of another set and the negative terminals of the clear signals and the negative terminals of the danger signals of different sets are respectively connected together, a time controlled switch interposed between the positive side of a supply source and said positive terminals to alternately energize the same, the negative terminals of the danger signals being connected in on the negative side of the supply source, a relay having a movable element connected to the negative terminals of the clear signals, and a pair of fixed contacts with either of which said movable element is engageable, one of the fixed contact-s being connected in on the negative side of the supply source and the other being connected in on the positive side of the supply source and an audible signal connected between said movable element and the negative side of said supply source, the relay including a plurality of additional movable members connected in on the positive side of the supply source, and fixed contacts respectively connected in between the time switch and the positive terminals of said signals, the last said contacts being engageable by the last said movable elements when the first said movable element is engaged with that contact connected in on the positive side of the supply source, the movable elements of the relay being spring actuated to normally engage the first said movable element with that contact connected in on the negative side of the supply source, and means to selectively control the relay to render it inactive or permit it to actuate the movable elements in opposition to the spring to engage all of them respectively with the other contacts.

In testimony whereof, I affix my signature.

DAVID HARLOlV CALDERWOOD. 

